人类脐血来源的间充质干细胞向软骨和成骨细胞分化的实验研究

Differentiation of Human Umbilical Cord Blood-derived Mesenchymal Stem Cells into Chondroblast and Osteoblasts

取足月剖宫产健康新生儿脐血,应用密度梯度法分离脐血单个核细胞,利用形态学特点和流式细胞仪检测细胞表面标志,鉴定和获取间充质干细胞。应用软骨诱导剂(10 ng/ml TGF-β、100 ng/ml胰岛素、10-7mol/L地塞米松、6.25μg/ml转铁蛋白)和成骨诱导剂(10 mmol/Lβ-甘油磷酸钠、50μg/ml维生素C、10-7mol/L地塞米松)定向诱导分化培养,以检测其是否具有分化能力。脐血来源的间充质干细胞表达CD13、CD44、CD73、CD90、CD166、HLA-AB,不表达CD34、CD45、HLA-DR。诱导分化21 d后,甲苯胺蓝染色和von-Kossa染色均显示阳性,免疫细胞化学结果显示脐血来源干细胞经软骨诱导后表达Ⅱ型胶原。表明脐血中存在着间充质干细胞,可在体外扩增培养,具有分化成软骨细胞与成骨细胞的能力。

Samples of healthy and full-term human umbilical cord blood samples were obtained asceptically. Mesenchymal stem cdls（MSCs） were isolated by lymphocyte separation medium, and were characterized morphologically by fluorescence-activated cell sorting analysis. Differentiation of chondroblast and osteoblast was induced by 10 ng/ml TGF-β, 100 ng/ml insulin and 10^-7 mol/L decaesadril, 6.25μg/ml sidemphilln, 10 mmol/L β-sodium glycemphosphate, 50μg/ml antiscorbic acid, respectirely; the aim was to investigate the potentiality of differentiation. Umbilical cord blood-derived MSCs were stained positive for MSCs marker CD13, CD90, CD166, CD73, CD44 and HLA-AB, but were negative for hematopoietic stem cell marker CD45, CD34 and HLA-DR. After 21 days induction, Toluidine Blue staining and von-Kossa staining were positive. Iiimaunocytochemistry showed that Collagen 1I expressed in the induced cells. The results demonstrated that mesenchymal stem cells can be isolated from human umbilical cord blood and differentiated into chondroblasts and osteoblasts in vitro.